An ongoing goal of biomaterials research is to improve the materials from which medical articles, such as medical devices and coatings for medical devices, are produced. An example of such a medical article is an implantable medical device.
A stent is an example of an implantable medical device that can benefit from improvements such as biocompatible coatings that can be used as a vehicle for delivering pharmaceutically active agents in a predictable manner.
Stents play an important role in a variety of medical procedures such as, percutaneous transluminal coronary angioplasty (PTCA). Stents act mechanically to hold open or expand a passageway within a subject. But thrombosis and restenosis, conditions that may arise months after a particular procedure, are among the problems associated with the use of stents and can lead to additional angioplasty or a surgical by-pass operation.
To address these problems, stents are being developed to locally delivery agents, such as drugs or biologics. In some embodiments, local delivery includes coating the surface of a medical article, e.g., a stent, with a polymeric carrier and attaching an agent to or blending an agent with the polymeric carrier. These agents are useful alone or in combination with other agents. But a major disadvantage of this method is that the agents are released from the matrix through variable polymeric matrix morphology As a result, local agent delivery to tissues can be considered unpredictable.
The present invention is directed to overcoming these and other deficiencies in the art.